<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
     <!-- 
        1. 引入 需要的依赖库
     -->
     <script src="https://cn.vuejs.org/js/vue.js"></script> 
     <!--  <script src="https://cdn.jsdelivr.net/npm/vue@2.6.11"></script> -->
     
</head>
<body>
    <div id="app">
       <!-- <p id="message">{{message}}</p>  -->
       <p v-if="condition">{{message}}</p>
       <p v-show="condition">{{message}}</p>
    </div>
</body>
<script>
    let vu = new Vue({
        el:"#app",
        data:{
            condition:true,
            //condition:false,
            message:"黑马程序猿"
        }
    })
</script>
</html>